In Spain, hundreds of thousands of women, wearing purple and raising their fists, took to the streets of cities around the country calling for greater gender equality.
The issue has become deeply divisive in Spain ahead of a national election on April 28. A new far-right party, Vox, has called for a 2004 law on domestic violence against women to be scrapped, and stands to win dozens of seats, opinion polls show.
Formal holiday in Berlin on Women's Day
In Berlin, city authorities declared Women's Day a formal holiday and thousands joined a colourful demonstration under sunny skies at the German capital's Alexanderplatz.
Protests for women's rights
In Paris, demonstrators from Amnesty International waved placards outside the Saudi Arabian embassy that read "Honk for women's rights", and called for the release of jailed women activists, including some campaigners for the right to drive in the deeply conservative kingdom.
In Athens and Kiev, women protesters demanded equality and an end to violence against women.
Police blocked protesters in Turkey
In Istanbul, Turkey's largest city, hundreds called for the release of Syrian women in jail. But in the evening, Turkish police fired tear gas to break up a crowd gathered for a march, Reuters witnesses said.
Hundreds of riot police blocked the marchers' path to prevent them from advancing along the district's main pedestrian avenue. Police then fired pepper spray and pellets containing tear gas to disperse the crowd, and scuffles broke out as they pursued the women into side streets off the avenue.
Decorated spaces in Russia
In Russia, where Women's Day has been an important festival since Communist times, flowers and congratulatory messages decorated public spaces.